On the formation of cinnamyl alcohol during the hydrogenation of cinnamaldehyde under mild conditions on supported palladium catalysts

The hydrogenation of cinnamaldehyde under mild conditions (293–343Â K; 1Â atm H2) by using Pd-based catalysts supported on different metal oxides (SiO2, Co3O4, Fe2O3) has been investigated. Compared to other supports, cobalt oxide was found to promote the catalytic properties of palladium effectively for the hydrogenation of the conjugated carbonyl group. The effect of the addition of Sn to Pd/Co3O4 and reaction temperature on the selectivity to cinnamyl alcohol was also evaluated. A low reaction temperature (293Â K) and a proper Sn loading (1 wt%) further enhance the selectivity of Pd/Co3O4 towards the desired unsaturated alcohol (up to 18.9Â % at 55Â % conversion of the substrate).